I’ve drunk it by the pot (not cup) since late teens – didn’t prevent cataracts that developed a year after diagnosis, though…but it could be of diabetic use, as it contains theophylline, which makes you more hypo-aware. It also inhibits absorption of iron, so don’t swallow your FeSO4-tablets with it.
Milk? Sugar? How could you put a lid on that tangy, bitter edge…do you add it to beer, too? 